PIE grammar made simple (1)

From: Piotr Gasiorowski
Message: 7217
Date: 2001-04-26

Those of you who'd like to write stories in good PIE will surely appreciate a condensed introduction to the most important grammatical features of PIE. I shall tackle PIE verbs first, explaining the system of aspects, tenses and moods, and the morphological processes involved in deriving complex verb stems from simpler verbs, nouns and adjectives.
To begin with, PIE has three verb aspects. Let us call them "durative", "aorist" and "perfect".
The durative includes imperfective or progressive meanings (prolonged, continuous or incomplete actions) and may also refer to repeated or habitual activity. It has preterite forms (a.k.a. imperfects) and present-tense forms (known as presents, for the sake of brevity).
The aorist expresses perfective or non-progressive meanings (completed actions). It does its job mainly in the preterite tense, where it functions rather like the English past simple. When used with non-preterite reference, it can function as the so-called injunctive (a kind of imperative).
The perfect (or stative) aspect denotes a present state resulting from an action.
The forms of the perfect are very characteristic. They usually involve reduplication (with the vowel *e) and a special kind of ablaut: the stressed o-grade of the root in the singular forms, and the unstressed nil or reduced grade in the plural:
  *le-lóikW-/*le-likW- ‘no longer hold’ (from *leikW- ‘abandon’)
  *me-món-/*me-mn- ‘remember’ (from *men- ‘think, consider’)
The distinction between durative and aorist verbs is trickier, since these aspects need not be overtly signalled. Verbs are regarded as inherently durative or aorist, and the marked (non-default) aspect is expressed by derived stems.
For example, the root *bHer- ‘carry’ is inherently durative, so the preterite *bHér-e-t (corresponding to the present *bHér-e-ti ‘he carries’) means ‘he was carrying’. To express a completed action, one would use a specially marked aorist form, in tis case *bHé:r-s-t ‘he carried, lifted’ (a so-called sigmatic aorist).
The aorist may also have a distinctive stress pattern (with stress falling on the thematic vowel), e.g. *bHug-é-t ‘he escaped’ as opposed to *bHéug-e-t ‘he was running away’, or employ reduplication, e.g. *we-ukW-é-t ‘he said’ as opposed to *wékW-t or *wékW-e-t ‘he was saying’.
Conversely, *doh3-t ‘he gave’ contains an aorist stem. To express the corresponding durative aspect (‘he was giving’), we can use a reduplicated stem with *i as the reduplication vowel, *di-doh3-t.
Furter examples:
  {jeug-} ‘connect’
DURATIVE  *junég-/*jung- (e.g. 3sg. pres. *junékti, 3pl. *jungénti)
AORIST    *jé:uk-s-/*jéuk-s- (e.g. 3sg. pret. *jé:ukst, 3pl. jéuksnt)
PERFECT   *je-jóug-/*je-jug- (e.g. 3sg. *jejóuge, 3pl. *jejugé:r)
  {gWHen-} ‘strike’
DURATIVE  *gWHén-/*gWHn-
AORIST    *gWHé:n-s-/*gWHén-s-
PERFECT   *gWHe-gWHón-/*gWHe-gWHn-
  {derk^-} ‘look’
DURATIVE  *dérk^e-
AORIST    *drk^é-
PERFECT   *de-dórk^-/*de-drk^-
Comments, corrections and questions welcome. If you like this crash course, I will convert the whole thing into HTML format and place it in the Cybalist "files" section.